package com.atguigu.gulimall.product.web;

import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import com.atguigu.gulimall.product.vo.Catelog2Vo;
import org.redisson.api.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

/**
 * @author zhangtao
 * @date 2022/10/8 - 21:40
 */
@Controller
public class IndexController {
    @Autowired
    CategoryService categoryService;

    @Autowired
    RedissonClient redissonClient;

    @Autowired
    StringRedisTemplate stringRedisTemplate;

    @GetMapping({"/", "/index.html"})
    public String indexPage(Model model) {
        //1、查出所有的一级分类
        List<CategoryEntity> categoryEntities = categoryService.getLevel1Categories();
        model.addAttribute("categories", categoryEntities);
        return "index";
    }

    @ResponseBody
    @GetMapping("/index/catalog.json")
    public Map<String, List<Catelog2Vo>> getCatalogJson() {
        Map<String, List<Catelog2Vo>> map = categoryService.getCatalogJson();
        return map;
    }

    @ResponseBody
    @GetMapping("/hello")
    public String hello() {
        //获取一把锁，只要锁的名字一样，就是同一把锁
        RLock lock = redissonClient.getLock("my_lock");
        //加锁
//        lock.lock();//阻塞式等待，默认加的锁都是30秒时间
        //锁的自动续期,如果业务超长，运行期间自动给锁续期上新的30秒，不用担心业务时间长，锁自动过期被删掉
        //加锁的业务只要运行完成，就不会给当前的锁续期，即使不手动解锁，锁默认也会在30s以后自动删除
        lock.lock(10, TimeUnit.SECONDS);//10s自动解锁,自动解锁时间一定要大于业务执行时间
        //在锁时间到了之后，不会续期
        //1、如果我们传递了锁的超时时间，就发送给redis执行脚本，进行占锁，默认超时时间就是我们指定的时间
        //2、如果未指定锁的超时时间，就是30*1000【LockWatchdogTimeout看门狗的默认时间】
        //      只要占锁成功，就会启动一个定时任务【重新给锁设置过期时间，新的过期时间就是看门狗的默认时间】
        //      internalLockLeaseTime【看门狗时间】/ 3,10s
        try {
            System.out.println("加锁成功，执行业务...." + Thread.currentThread().getId());
            Thread.sleep(30000);
        } catch (InterruptedException e) {
        } finally {
            //解锁
            System.out.println("释放锁....." + Thread.currentThread().getId());
            lock.unlock();
        }
        return "hello";
    }

    //保证一定能读到最新数据,修改期间，写锁是一个排他锁（互斥锁，独享锁）,读锁是一个共享锁
    //写锁没释放就必须等待
    //读 + 读 : 相当于无锁状态,并发读，只会在redis中记录好，所有当前的读锁，他们都会同时加锁成功
    //写 + 读：等待写锁释放
    //写 + 写：阻塞方式
    //读 + 写：有读锁，写也需要等待
    //只要有写的存在，都必须等待
    @GetMapping("/write")
    @ResponseBody
    public String writeValue() {
        RReadWriteLock lock = redissonClient.getReadWriteLock("rw_lock");
        String s = "";
        RLock rLock = lock.writeLock();
        try {
            //改数据加写锁，读数据加写锁
            rLock.lock();
            System.out.println("写锁加锁成功...." + Thread.currentThread().getId());
            s = UUID.randomUUID().toString();
            Thread.sleep(30000);
            stringRedisTemplate.opsForValue().set("writeValue", s);
        } catch (Exception e) {
        } finally {
            rLock.unlock();
            System.out.println("写锁释放...." + Thread.currentThread().getId());
        }
        return s;
    }


    @GetMapping("/read")
    @ResponseBody
    public String readValue() {
        RReadWriteLock lock = redissonClient.getReadWriteLock("rw_lock");
        //加读锁
        RLock rLock = lock.readLock();
        rLock.lock();
        System.out.println("读锁加锁成功...." + Thread.currentThread().getId());
        String s = "";
        try {
            s = stringRedisTemplate.opsForValue().get("writeValue");
            Thread.sleep(30000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            rLock.unlock();
            System.out.println("读锁释放...." + Thread.currentThread().getId());
        }

        return s;
    }

    /**
     * 车库停车
     * 3车位
     * 信号量也可以做分布式限流
     */
    @GetMapping("/park")
    @ResponseBody
    public String park() throws InterruptedException {
        RSemaphore park = redissonClient.getSemaphore("park");
//        park.acquire();//获取一个信号,获取一个值,占一个车位
        boolean b = park.tryAcquire();
        if (b) {
            //执行业务
        } else {
            return "error";
        }
        return "ok=>" + b;
    }

    @GetMapping("/go")
    @ResponseBody
    public String go() throws InterruptedException {
        RSemaphore park = redissonClient.getSemaphore("park");
        park.release();//释放一个车位
        return "ok";
    }

    /**
     * 放假，锁门
     * 5个班全部走完，我们可以锁大门
     */
    @GetMapping("/lockDoor")
    @ResponseBody
    public String lockDoor() throws InterruptedException {
        RCountDownLatch door = redissonClient.getCountDownLatch("door");
        door.trySetCount(5L);
        door.await();//等待闭锁完成
        return "放假了....";
    }

    @GetMapping("/gogogo/{id}")
    @ResponseBody
    public String gogogo(@PathVariable("id") Long id) {
        RCountDownLatch door = redissonClient.getCountDownLatch("door");
        door.countDown();//计数减1
        return id + "班的人都走了...";
    }
}
